Cut the pork in small dice. In a saucepan on medium heat place the butter. When the butter starts foaming add the diced meat. Sauté and cook the meat until lightly browned. Transfer the meat to a food processor. Pulse a few times to reduce to a coarse compound. Add the mortadella and prosciutto to the processor. Run the blade until all the meat is very finely ground.Transfer the ground meat to a shallow bowl. Add the egg, the freshly grated nutmeg, and the grated parmigiano reggiano. Combine all ingredients very thoroughly together.Prepare pasta dough using my pasta dough recipe. Make the dough very soft, using just enough flour to avoid the dough sticking to the hands while working. Flatten the dough with the rolling pin or machine. Divide the dough in several pieces. Place one piece on the work surface and set the rest aside. Cover the reserved dough with plastic wrap to prevent it from drying.Cut the dough in squares 1-1/2 inch (4 cm) approximately.Place approximately one teaspoon of the filling in the center of each square.To form the tortellini:Take one of the pasta squares. Fold it in half. Press on the edges to form a triangle. Fold the tip of the triangle. Wrap the triangle around your index finger. Close it in a ring shape pressing gently on the pasta to hold its shape.The recipe will make approximately 300 tortellini, enough for 6 to 8 people.Place approximately 1-½ quart (1500 cc) of the broth to a boil. When the broth is at a fast boil drop the tortellini.Cook the tortellini until “al dente” (firm but not too soft or overcooked.) Cooking time may vary depending on the freshness of the tortellini. Dried tortellini may take a little longer then freshly made tortellini.Place the tortellini in serving bowls, top with freshly grated parmigiano reggiano cheese, and optionally, with freshly grated nutmeg.